Thermometers which utilize bimetallic elements for indicating a surrounding temperature have been well known. Examples of such construction are seen, for example, in the U.S. Pat. Nos. 2,771,775 (374-208) and 1,897,814 (374-1). It is often desired to view the outside temperature through a window and to this end, it has been customary to provide thermometers that in some way could be mounted outdoors and be viewed through a window. Mounting thermometers by virtue of utilizing suction cups are generally known, as seen for example, in U.S. Pat. Nos. 2,117,012 and Des. 123,117 but items such as these, while they discloses the concept of attaching a thermometer on a window, the units are of a size and utility render them hard to read unless one is close to the window. Desirably, therefore, an ideal thermometer for mounting on a window pane for viewing the outside temperature should be of a sufficient size and of a stable mount so that it is fully usable.